In the related art, as described in, for example, JP 07-031596 U (Reference 1), a printed circuit board accommodation casing, which accommodates a printed circuit board mounted with a control circuit, may include a pair of guide portions provided on the inner wall surface of the accommodation casing with the printed circuit board accommodated in the accommodation casing being sandwiched between the guide portions in the thickness direction. That is, such an accommodation casing holds the printed circuit board in such a manner that side end portions of the printed circuit board are inserted between both guide portions. In the accommodation casing in this example in the related art, an engagement protrusion is formed to protrude from one side to the other side of both projecting portions. In addition, a crushing margin that is crushed by an insertion pressure of the printed circuit board inserted between both projecting portions in the extending direction is set at the distal end of the engagement protrusion so that the printed circuit board is more reliably held with a clamping pressure.
However, in the configuration of the above described technology in the related art, there is a possibility that a gap of tolerance may be formed between the side end portions of the printed circuit board and the inner wall surface of the accommodation casing on which both guide portions are provided. Therefore, for example, under a vibrating environment such as a control device for a vehicle, there is a problem in that a rattling of the printed circuit board occurs due to the gap in the planar direction. In addition, when a clamping pressure in the thickness direction is strengthened so as to suppress such a rattling of the printed circuit board, there is a risk that the printed circuit board may be deflected. Thus, in this regard, there is still room for improvement.
Thus, a need exists for a printed circuit board accommodation casing which is not susceptible to the drawback mentioned above.